WO2004035377A1

WO2004035377A1 - Surfboard fin box

Info

Publication number: WO2004035377A1
Application number: PCT/AU2003/001380
Authority: WO
Inventors: John Milne Decourcey
Original assignee: Decourcey Pty Ltd
Priority date: 2002-10-17
Filing date: 2003-10-17
Publication date: 2004-04-29

Abstract

A surfboard fin box including a body (11) having an elongate dimension, a transverse dimension at right angles to the elongate dimension and a depth dimension at right angles to the elongate and transverse dimensions; a first open cavity (18) extending into the body in the depth dimension and adapted to reveice one or more tabs of a fin; a second open cavity (19) spaced in the transverse dimension from the first open cavity and extending in the depth dimension into the body; bearing means (22) extending in the transverse dimension between the first and second cavities (18, 19) and adapted to bear in the transverse dimension against the side face of the one or more tabs; and actuation means operably associated with the bearing means (22) to move the bearing means (22) towards and away from the one or more tabs.

Description

"SURFBOARD FINBOX"

FIELD OFINVENTION

THIS INVENTION relates to a surfboard fin box. Although the invention has particular application to surfboards, the invention is not limited to this field of use.

BACKGROUND ART

The fins of surfboards have recently become the subject of some improvements, particularly in relation to their attachment to the main part of the surfboard. Generally, the improvements have been aimed at providing for removable fins thereby providing for the attachment of different fins selected to suit different conditions in the surf or in the style of surfing to be performed. One example is disclosed in Australian Patent No. 657456, in which a removable fin system for surfboards and the like includes a fin having tabs extending from the proximal end which are receivable into complementary cavities of plugs embedded in the board. An obliquely extending grub screw is used to secure the fin by its tabs in the cavities by bearing against a side face of the tabs, one screw for each tab. The plugs can be in the form of a fin box, this latter being a common intermediate device used for attaching fins to boards. However, the angular orientation of the grub screw does not necessarily result in the securing force effected by the screw on the tabs of the fin acting in the most desirable fashion.

A similar arrangement is disclosed in Australian Patent Specification No. 81502/94, except that the cavity into which the tab is inserted has a flexible wall against one side, a slot being provided on the other side of the flexible wall from the cavity and instead of a grub screw bearing directly against the side of the tab extension of the fin, a "fastener" in the form of a plug is insertable into the slot to prevent removal of the tab by preventing the flexible wall from flexing by virtue of the presence of the fastener in the slot.

In Australian Patent Specification No. 707856, the tabs on the fin are cruciform in section and correspond to complementary cruciform-section cavities in respective plugs each acting as a kind of fin box. An oblique grub screw arrangement is provided in similar fashion to that of Australian Patent No. 657456 hereinbefore described, except that each respective grub screw bears against one of the lateral faces of the respective tabs of the fin.

In Australian Patent Specification No. 34367/02, a fin box is provided having the same arrangement, except that by a simple combination of the arrangements of Australian Patent No. 657456 and Australian Patent Specification No. 81502/94, the oblique grub screw bears against a flexible wall interposed between the cavity into which the tab of a fin is receivable and a slit to provide for movement of the flexible wall when the grub screw is inserted therein to bear against face of the flexible wall remote from the cavity.

Some of the fin boxes of the prior art rely upon a clamping force being applied to one or more tabs extending from the proximal portion of a fin or the proximal portion of the fin itself. Such arrangements sometimes permit the clamping force to exceed the strength of the fin box, resulting in splitting of the fin box and consequential loosening of the fin clamped therein. Once structural failure of the fin box occurs, the clamping force cannot be satisfactorily applied.

The present invention aims to provide a surfboard fin box which alleviates one or more of the disadvantages of the prior. art. Other aims and advantages of the invention may become apparent from the following description. DISCLOSURE OF THE INVENTION

With the foregoing in view, this invention in a first aspect resides broadly in a surfboard fin box including:

a body having an elongate dimension, a transverse dimension substantially at right angles to the elongate dimension and a depth dimension generally at right angles to the elongate and transverse dimensions;

a first open cavity extending into the body in the depth dimension and adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin;

a second open cavity spaced from the first open cavity in the transverse dimension and extending into the body in the depth dimension, and having its opening in the same direction as the opening of the first open cavity;

bearing means extending substantially transversely between the first and second cavities in the transverse dimension and adapted to bear against the side face of the one or more tabs or proximal portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity; and

actuation means operably associated with the bearing means for actuating the bearing means towards and away from operative engagement against the one or more tabs or proximal portion of the fin, said actuation means being accessible by way of the second cavity;

wherein the bearing means is not substantially moveable in any dimension other than the transverse dimension.

In a second aspect, the present invention resides broadly in a surfboard fin box including: a body having an elongate dimension, a transverse dimension substantially at right angles to the elongate dimension and a depth dimension generally at right angles to the elongate and transverse dimensions;

an open cavity extending into the body in the depth dimension and adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin;

bearing means operatively associated with the body and adapted to apply a clamping force substantially transversely between the periphery of the cavity in the transverse dimension to bear against the side face of the one or more tabs or proximal portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity;

actuation means operably associated with the bearing means for , actuating the bearing means towards and away from operative engagement against the one or more tabs or proximal portion of the fin, said actuation means being accessible by way of the second cavity; and

binding means surrounding the body for binding the body against expansion resulting from the operative engagement of the bearing means against the one or more tabs or proximal portion of the fin.

In the first aspect, it is preferred that binding means surrounds the body for binding the body against expansion resulting from the operative engagement of the bearing means against the one or more tabs or proximal portion of the fin. In the second aspect, it is preferred that the cavity be provided in the form of a first open cavity extending into the body in the depth dimension and adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin and a second open cavity spaced from the first open cavity in the transverse dimension and extending into the body in the depth dimension, and having its opening in the same direction as the opening of the first open cavity. In such form it is also preferred that the bearing means extend substantially transversely between the first and second cavities in the transverse dimension and adapted to bear against the side face of the one or more tabs or proximal portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity.

Preferably, the first cavity comprises a single cavity and a plurality of bearing means extend between the first cavity and a corresponding plurality of second cavities . The or each bearing means is preferably formed in the manner of a threaded member extending transversely through a threaded bore extending between the first and second cavities . In such form, the threaded member may be moved axially by rotation about its axis.

The actuation means is preferably formed as a head or the like on the end of the threaded member, the head or the like being located substantially within the second cavity. In one form, the head is in the form of a roller of larger diameter than the threaded member and in fixed rotational relationship therewith. In such form, the roller is arranged such that part of its periphery protrudes above the opening of the second cavity. The head may also be arranged to be slidable in the axial direction with respect to the threaded member whereby the threaded member may be moved by frictional engagement of the periphery of the roller substantially tangentially to effect rotation thereof and in turn the rotation and consequential axial movement of the threaded member. In an alternative form, the head is in the form of a hexagonal head or the like contained entirely within the second cavity, and being engageable by a spanner or the like to rotate the head and threaded member to cause the axial movement of the threaded member.

In another alternative form, the head is in the form of a keyway or hexagonal socket in the end of the threaded member nearer the second cavity, and suitable for receiving a key, such as a hexagonal key or alien key or wrench to rotate threaded member to cause the axial movement of the threaded member.

In an alternative form, the bearing means is a composite bearing means including a bearing element and a displacement element. In one form, the bearing element is in the form of a resiliently deformable wall interposed between the first and second cavities and the displacement element is a threaded member moveable substantially exclusively in the transverse dimension to deform the deformable wall against the side face of the tab of a fin when operatively inserted in the first cavity.

In another alternative form, the bearing means is formed as a separate moveable element which has opposed bearing faces. The arrangement of the opposed bearing faces and the second cavity are such that the operative displacement of the bearing element in a dimension other than the transverse dimension, such as in the elongate dimension or rotationally, causes a net transverse displacement of one bearing face against the side face of the tab of a fin operatively inserted into the first cavity. The displacement of the bearing element is operatively effected by the provision of a displacement element substantially as hereinbefore described.

In another aspect, this invention resides broadly in a surfboard fin box including: a body having an elongate dimension, a transverse dimension substantially at right angles to the elongate dimension and a depth dimension generally at right angles to the elongate and transverse dimensions;

an open cavity extending into the body in the depth dimension and having a first cavity portion adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin and a second cavity portion spaced from the first cavity portion in the transverse dimension;

a bearing element operatively interposable between the first and second cavity portions in the transverse dimension and including a bearing fact portion adapted to bear against the side face of the one or more tabs or proximal portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity portion; and

actuation means operably associated with the bearing element for operatively moving the bearing element towards and away from operative engagement against the one or more tabs or proximal portion of the fin, said actuation means being accessible by way of the second cavity portion;

wherein the bearing element is moveable in one or more dimensions including the transverse dimension.

In such form, it will be seen that the first and second cavity portions are operatively separated from one another by the bearing element. Of course, there may be more than one of either of the first and second cavity portions associated with one another. It is preferred that the bearing element be movable in a single dimension only having a component in the transverse dimension. For example, the bearing element may be slidingly movable predominantly in the elongate dimension, but bear against a complementary bearing surface of the second cavity portion which is tapered in the elongate dimension whereby movement in the elongate dimension results in a smaller, but sufficient movement in the transverse dimension to enable the bearing element to exert a bearing force against the tabs of a fin when into the first cavity portion. It is also preferred that binding means surrounds the body for binding the body against expansion resulting from the operative engagement of the bearing means against the one or more tabs or proximal portion of the fin.

The binding means is preferably in the form of a band of substantially inextensible textile material, such as fibreglass matting, webbing, cloth or the like. It will be appreciated that other materials exhibiting hoop strength characteristics may be used for binding the body of the fin box against splitting as a result of internal forces applied corresponding to the clamping force applied to the fin. The binding means is suitably sized to provide a relatively tight fit about the body, the body preferably having a rounded shape. The band is preferably bonded to the body of the fin box prior to insertion into the surf craft.

It is believed that the arrangement of transverse movement of the bearing means substantially without movement in the other dimensions causes less damage to the tab or tabs of a fin member and enables greater transverse clamping than the arrangements of the prior art.

BRIEFDESCRIPTION OFTHF, DRAWINGS

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein: - Fig. 1 is a diagrammatic view of a first preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 2 is a diagrammatic sectional view of the surfboard fin box of Fig. 1 on line 2-2 of Fig. 3 viewed in the depth dimension;

Fig. 3 is a diagrammatic sectional view of the surfboard fin box of Fig. 1 on line 3-3 of Fig. 2 viewed in the elongate dimension;

Fig. 4 is a diagrammatic view of a second preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 5 is a diagrammatic sectional view of the surfboard fin box of Fig. 4 on line 5-5 of Fig. 7 viewed in the depth dimension;

Fig. 6 is a diagrammatic sectional view of the surfboard fin box of Fig. 4 on line 6 - 6 of Fig. 5 viewed in the elongate dimension;

Fig. 7 is a diagrammatic sectional view of the surfboard fin box of Fig. 4 on line 7-7 of Fig. 5 viewed in the transverse dimension;

Fig. 8 is a diagrammatic sectional view of the surfboard fin box of Fig. 6, but slightly modified;

Fig. 9 is a diagrammatic sectional view of a third preferred surfboard fin box according to the invention viewed in the depth dimension on line 9-9 of Fig. 10; Fig. 10 is a diagrammatic sectional view of the surfboard fin box of Fig. 9 on line 10-10 of Fig. 9 viewed in the elongate dimension;

Fig. 11 is a diagrammatic view of the surfboard fin box of Figs 9 and 10 viewed in the depth dimension;

Fig. 12 is a diagrammatic sectional view of the surfboard fin box of Fig. 11 showing partial application of the bearing means;

Fig. 13 is a diagrammatic sectional view of the surfboard fin box of Fig. 12 along line 13-13 of Fig. 12 viewed in the elongate dimension;

Fig. 14 is a diagrammatic view of the surfboard fin box of Figs. 11 and 12 viewed in the transverse dimension on line 14-14 of Fig. 13;

Fig. 15 is an exploded side elevation of a part of a surfboard fin box according to the invention showing operative disposition of the surfboard fin box with respect to a fin;

Fig. 16 is a diagrammatic view of a fourth preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 17 is a diagrammatic sectional view of the surfboard fin box of Fig. 16 along line 17-17 of Fig. 20 showing retraction of the bearing means viewed in the depth dimension;

Fig. 18 is a diagrammatic sectional view of the surfboard fin box of Fig. 16 also along line 17-17 of Fig. 20 showing partial application of the bearing means viewed in the depth dimension; Fig. 19 is a diagrammatic sectional view of the surfboard fin box of Figs 16 to 18 along line 19-19 of Fig. 16 viewed in the elongate dimension;

Fig. 20 is a diagrammatic sectional view of the surfboard fin box of Figs 16 to 18 along line 20-20 of Fig. 16 viewed in the elongate dimension;

Fig. 21 is a reproduction of diagrammatic sectional view of the surfboard fin box of Fig 20 showing its operative disposition with respect to a surfboard fin viewed in the elongate dimension;

Fig. 22 is a diagrammatic view of a fifth preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 23 is a diagrammatic view of the surfboard fin box of Fig. 22 showing a bearing element in its operative position;

Fig. 24 is a diagrammatic view of a sixth preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 25 is a diagrammatic view of the surfboard fin box of Fig. 24 showing two bearing elements in their respective operative positions;

Fig. 26 is a diagrammatic view of a seventh preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 27 is a diagrammatic view of the surfboard fin box of Fig. 26 showing a bearing element in its operative position; Fig. 28 is a diagrammatic sectional view of the surfboard fin box of Fig. 26 along line 28-28 viewed in the elongate dimension;

Fig. 29 is a diagrammatic sectional view of the surfboard fin box of Fig. 27 along line 27-27 viewed in the elongate dimension.

Fig. 30 a diagrammatic view of an eighth preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 31 is a diagrammatic view of the surfboard fin box of Fig. 30 showing a bearing element in its operative position;

Fig. 32 a diagrammatic view of a ninth preferred surfboard fin box according to the invention viewed in the depth dimension;

Fig. 33 is a diagrammatic sectional view of the surfboard fin box of Fig. 32 along line 32-32 viewed in the elongate dimension in a clamping attitude;

Fig. 34 is a diagrammatic sectional view of the surfboard fin box of Fig. 32 along line 32-32 viewed in the elongate dimension in a non-clamping attitude; and

Fig. 35 is an exploded pictorial diagrammatic representation of a fin box and binding means according to the invention.

DETAILED DESCRIPTION OFTHE DRAWINGS

The first surfboard fin box 10 shown in Figs. 1 to 3 includes a body 11 formed as an elongate rectangular prism having an external face 12, an internal face 13 spaced therefrom and parallel thereto, two side faces 14 and 15 extending between the internal and external faces substantially at right angles, and two end faces 16 and 17 substantially at right angles to the internal, external and side faces. The internal and external faces provide the extremities of the depth dimension of the body; the side faces provide the extremities of the transverse dimension of the body; and the end faces provide the extremities of the elongate dimension of the body.

An elongate first open cavity 18 is provided in the body, open to the external face. The first cavity is shown in rectilinear form having side walls parallel to the side faces of the body, a base wall parallel to the internal face and end walls parallel to the end faces of the body. It will be appreciated that the first cavity would be shaped or configured to accommodate a wide range of existing kinds of fin shape. A set of second open cavities (each having the reference numeral 19) is also provided in the body spaced from the first cavity in the transverse dimension and from one another in the elongate dimension. Each second cavity is rectilinear in form having one side wall parallel to the side faces of the body, a base wall parallel to the internal face and end walls parallel to the end faces of the body in similar fashion to that which is depicted in respect of the first cavity. However, the second cavities also have an access passage 20 penetrating an external wall, the access passages also being rectilinear in form, having their two end walls each in a common plane with the respective end walls of the second cavities and side walls spaced inwardly from the side walls of the second cavities. Additionally, the second cavities are also open to the side face 14 remote from the first cavity.

A threaded bore 21 is provided extending between each second cavity and the first cavity in the transverse dimension. A hexagonal headed machine screw 22 is provided in each bore (though one is removed from the views depicted for clarity) . Additionally, a side cover 23 is provided to close the opening in the side face to prevent intrusion of resin into the cavities when the fin box is being installed into a board. By rotating the machine screw about its axis, screw may be moved towards the side face of the proximal end portion or proximally extending tabs of a surfboard fin such that the end thereof may be clamped thereagainst or moved away therefrom.

The second surfboard fin box 40 shown in Figs. 4 to 8 is the same in many respects to the first surfboard fin box. Accordingly, the same reference numerals are used to refer to similar or the same parts or elements. However, the differences are described hereinafter. A body 41 is provided with a pair of second cavities 42, each having a D-shaped section in the depth dimension, a triangular section in the transverse dimension, and a rectangular section in the elongate dimension. A grub screw 43 is provided in each threaded bore between the first and second cavities. The end of each grub screw nearer the second cavity is provided with a hexagonal socket 44 which permits an alien key to be used to turn the grub screws about their respective axes . The sloping sides of the second cavities accommodate the swing of the alien key in turning the grub screws .

In the slightly modified version shown in Fig. 8, the threaded bore is replaced by a captive nut 45 provided in a lower facing aperture 46 and capped with an internal face cover 47. In such form, the threaded engagement of the grub screw is more robust since the captive nut can be made- from a stronger material than is generally used for the construction of fin boxes.

The third surfboard fin box 80 shown in Figs. 9 to 14 is the same in many respects to the first and second surfboard fin boxes . Accordingly, the same reference numerals are used to refer to similar or the same parts or elements. However, the differences are described hereinafter. A body 81 has rounded ends 82 at each end. The rounded ends are of semicircular form when viewed along the depth dimension, but having progressively increasing concavity from the side faces to the apices of the ends when viewed along the transverse dimension. A pair of second cavities 83 is provided opening to the external face, each having a lenticular section in the depth dimension, a triangular section in the transverse dimension, and a rectangular section in the elongate dimension, but also having a cylindrical portion 87 seen more particularly in Fig. 12 extending in the transverse dimension away from the first cavity.

Two hexagonal-headed machine screws 84 are fixedly embedded into the body with their heads remote from the second cavities and the threaded shafts extending across the first cavity in the transverse dimension and into the second cavities respectively. A knurled nut 87 is threaded engaged on each machine screw and each nut includes a plurality of engagement apertures shown typically at 86 about its periphery. The apertures extend part way radially into each nut to provide for insertion of a tool of complementary configuration to effect a tangential force upon the nut to turn it with respect to the machine screw to effect transverse movement of the nut towards and away from the first cavity. A resiliently displaceable wall portion 88 as shown in particular in Fig. 12 is interposed between each nut and the first cavity to permit reduction of the transverse dimension of the first cavity to provide clamping engagement of the side walls of the first cavity with the side faces of the tabs or proximal portion of a surfboard fin when inserted therein.

In use, the tabs 78 of a fin 89, part of which is shown in Fig. 15, may be inserted into the first cavity of the fin box in the direction of arrow 77 and clamped therein in accordance with the above described transverse displacement of the resiliently displaceable portion.

The fourth surfboard fin box 90 shown in Figs. 16 to 21 is the same in many respects to the first, second and third surfboard fin boxes. Accordingly, the same reference numerals are used to refer to similar or the same parts or elements . However, the differences are described hereinafter. A body 91 has rounded ends 92 at each end. The rounded ends are of asymmetric form when viewed along the depth dimension and have progressively increasing convexity from the side face adjacent the second cavities to the side face adjacent the first cavity. Two second cavities 93 are provided in the form of a threaded bore portion and a cylindrical portion. Each of the second cavities has a serrated nut 94 rotatably mounted on a threaded rod 95, the second cavities having an axis in the transverse dimension, whereby rotation of the nut will effect axial movement of the threaded rod. A moveable member 96 is interposed between the first and second cavities and may be forced against the side faces of the tabs or proximal portion of a fin inserted into the first cavity. In the embodiment shown in Figs. 16 to 21, the first cavity includes a sloped portion 97 at each end as shown in particular in Fig. 19 to permit the fin to be tilted to an oblique angle with respect to the depth dimension.

The fifth surfboard fin box 100 shown in Figs. 22 and 23 includes a body 101 having similarities to the bodies of the first four fin boxes hereinbefore described, and therefore, the same reference numerals have been used to refer to similar features. However, the differences are described hereinafter. The side face nearer the first cavity is substantially straight, but the opposed side has two oblique faces 102 and 103 which diverge from the rounded ends to an obtuse rounded vertex 104 such that the body can accommodate a circular second cavity 105 having a dog pinion 106 mounted therein for partial rotation about an axis oriented in the depth dimension. The dog pinion has a lug 107 extending radially from one side to engage with a groove 109 provided in one side of a wedge 108. The first cavity is tapered in corresponding angularity with the taper of the wedge so that movement of the wedge caused by rotating the dog pinion causes a bearing face 112 if the wedge towards the opposed face of the first cavity. The wedge also has a plurality of fixing apertures shown typically at 110 into which a pin 111 may be fixed to lock the wedge in a desired longitudinal disposition within the first cavity to suit the amount of clamping of the wedge against the side face of the tab of a fin when mounted therein. It can be seen that with the wedge moved relatively to the right in Fig. 23 as compared to its location in Fig. 22, the bearing face of the wedge is closer to the opposite internal face of the first cavity. The dog pinion is turned by inserting an alien key or the like into a hexagonal aperture 112 in the exposed face of the dog pinion.

The sixth surfboard fin box 120 shown in Figs. 24 and 25 includes a body 121 having similarities to the bodies of the five fin boxes hereinbefore described, and therefore, the same reference numerals have been used to refer to similar features . However, the differences are described hereinafter. The side face nearer the first cavity is substantially straight as in the other fin boxes, but the opposed side has two lobes 123 which diverge from the rounded ends at 121, with an intermediate face 124 between the lobes. Each lobe is of a size to accommodate a cam button shown typically at 126 in its respective circular secondary cavity shown typically at 125 which can pivot about a pivot centre portion shown typically at 127. It can be seen that by so pivoting the cam buttons from the positions shown in Fig. 24 to the positions shown in Fig. 25, part of the periphery of the cam buttons extends into the first cavity. Such pivoting enables that part of the outer face of each cam button to bear against the side face of the tab of a fin when operatively inserted into the first cavity.

The seventh surfboard fin box 140 shown in Figs. 26 to 28 includes a body 141 having similarities to the bodies of the six fin boxes hereinbefore described, and therefore, the same reference numerals have been used to refer to similar features. However, the differences are described hereinafter. The side face nearer the first cavity is substantially straight as in the other fin boxes, but the opposed side has two lobes 143 each with a convex face 142, with an intermediate face 144 between the lobes. Each lobe is sized to accommodate an obliquely arranged grub screw 148 which is threadedly engaged by its threaded shaft with a threaded aperture 144 extending obliquely into a second cavity 145 as can be seen more particularly in Figs. 28 and 29. The grub screws are captured for rotation in a bearer 147 , and the cross-section of the bearer is arranged to match the profile of the second cavity, but also to provide a substantially straight bearing face 149 for bearing against the side face of the tab of a fin when operatively inserted into the first cavity.

The eighth surfboard fin box 150 shown in Figs. 30 and 31 includes a body 151 having similarities to the body of the surfboard fin boxes hereinbefore described, particularly that in Figs. 11 to 14, and therefore, the same reference numerals have been used to refer to similar features. However, instead of two second cavities, a single second cavity 83 is provided such that there is a single resiliently displaceable wall portion 88 between the first and second cavities. The ninth surfboard fin box 160 shown in Figs. 32 to 34 includes a body 151 and a first cavity 18 similar to embodiments previously described herein, with the exception that the cavity is trapezoidal in shape to provide an angled bearing face against which a wedge block 162 is can bear. The wedge block has a complementary shape to that of the cavity to permit the face opposite the bearing face to be substantially parallel to the opposed internal face of the cavity. A lever arm 163 is provided in pivotal connection with both the wedge block and the body of the fin box at a block pivot 165 connecting the lever arm to the wedge block and at a body pivot 167 connecting the lever arm to the body of the fin box. The block pivot engages with a slot 166 in the wedge block to accommodate the depth dimension displacement of the block pivot with the lever arm is pivoted about the body pivot. Complementary curved bearing faces 164 are provided on the distal end of the lever arm and in the wedge block to accommodate the bearing force applied in the direction of arrow 169 when levering the wedge block in the same direction. It can be seen that by adopting the appropriate angular relationship between the wedge block and the fin, a transverse displacement of the wedge block can be effected to clamp the fin in the fin box. Additionally, the wedge block has a complementary cavity to receive the lever arm which is also shaped such that when in the clamping attitude as shown in Fig. 33, the lever arm does not protrude significantly out from the adjacent face of the surf craft.

The surfboard fin box 170 shown in Fig. 35 is shown diagrammatically in circular form with the first and second cavities 18 and 19 shown therein also in diagrammatic form. The outer face 172 of the fin box body bears against the inner face

173 of a binding 174. In use, a surfboard fin box in accordance with the invention is inserted into a board for a surfboard during the manufacturing process prior to the shaping of the board, and is bonded into the board in the normal manner, the side covers, if required, being placed in the side faces of the surfboard box to prevent intrusion of materials, such as fibreglass resin, into the second cavities. The fin box is manufactured from materials which can be sanded down to the shape of the board as required, and, by virtue of the transverse clamping, is believed to provide a system which is superior to alternative systems which sometime introduce a non-transverse force component in the clamping action. The binding gives the fin box greater strength against splitting of the body when the lateral force is applied in response to the clamping forces applied to the fin.

Although the invention has been described with reference to specific examples, it will be appreciated by persons skilled in the art that the invention may be embodied in other forms within the broad scope and ambit of the invention claimed by the following claims .

Claims

1. A surfboard fin box including: a body having an elongate dimension, a transverse dimension substantially at right angles to the elongate dimension and a depth dimension generally at right angles to the elongate and transverse dimensions; a first open cavity extending into the body in the depth dimension and adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin; a second open cavity spaced in the transverse dimension from the first open cavity and extending in the depth dimension into the body, and having its opening in the same direction as the opening of the first open cavity; bearing means extending in the transverse dimension substantially transversely between the first and second cavities and adapted to bear in the transverse dimension against the side face of the one or more tabs or proximal portion of the fin when the fin is operatively inserted into the first cavity; and actuation means operably associated with the bearing means for actuating the bearing means towards and away from operative engagement against the one or more tabs or proximal portion of the fin, said actuation means being accessible by way of the second cavity; wherein the bearing means is not substantially moveable in any dimension other than the transverse dimension.

2. A surfboard fin box including: a body having an elongate dimension, a transverse dimension substantially at right angles to the elongate dimension and a depth dimension generally at right angles to the elongate and transverse dimensions; an open cavity extending into the body in the depth dimension and adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin; bearing means operatively associated with the body and adapted to apply a clamping force substantially transversely between the periphery of the cavity in the transverse dimension to bear against the side face of the one or more tabs or proximal portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity; actuation means operably associated with the bearing means for actuating the bearing means towards and away from operative engagement against the one or more tabs or proximal portion of the fin, said actuation means being accessible by way of the second cavity; and binding means surrounding the body for binding the body against expansion resulting from the operative engagement of the bearing means against the one or more tabs or proximal portion of the fin.

3. A surfboard fin box according to Claim 1, and including binding means surrounds the body for binding the body against expansion resulting from the operative engagement of the bearing means against the one or more tabs or proximal portion of the fin.

4. A surfboard fin box according Claim 2, wherein the cavity is provided in the form of a first open cavity extending into the body in the depth dimension and adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin and a second open cavity spaced from the first open cavity in the transverse dimension and extending into the body in the depth dimension, and having its opening in the same direction as the opening of the first open cavity.

5. A surfboard fin box according to Claim 4, wherein the bearing means extend substantially transversely between the first and second cavities in the transverse dimension and adapted to bear against the side face of the one or more tabs or proximal

5 portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity.

6. A surfboard fin box according to Claim 1 or Claim 3, wherein the first cavity comprises a single cavity and a

10 plurality of bearing means extend between the first cavity and a corresponding plurality of second cavities .

7. A surfboard fin box according to Claim 6, wherein the or each bearing means is formed in the manner of a threaded member

15 extending transversely through a threaded bore extending between the first and second cavities, whereby the threaded member may be moved axially by rotation about its axis .

8. A surfboard fin box according to Claim 7, wherein the

20 actuation means is formed as a head or the like on the end of the threaded member, the head or the like being located substantially within the second cavity.

9. A surfboard fin box according to Claim 8 , wherein the head 25 is in the form of a roller of larger diameter than the threaded member and in fixed rotational relationship therewith arranged such that part of its periphery protrudes above the opening of the second cavity.

30 10. A surfboard fin box according to Claim 9, wherein the head is arranged to be slidable in the axial direction with respect to the threaded member whereby the threaded member may be moved by frictional engagement of the periphery of the roller substantially tangentially to effect rotation thereof and in turn the rotation and consequential axial movement of the threaded member.

5 11. A surfboard fin box according to Claim 10, wherein the head is in the form of a hexagonal head or the like contained entirely within the second cavity, and being engageable by a spanner or the like to rotate the head and threaded member to cause the axial movement of the threaded member. 10

12. A surfboard fin box according to Claim 10, wherein the head is in the form of a keyway or hexagonal socket in the end of the threaded member nearer the second cavity.

15 13. A surfboard fin box according to any one of Claims 1, 3, 9 or 10, wherein the bearing means is a composite bearing means including a bearing element and a displacement element.

14. A surfboard fin box according to Claim 13, wherein the

20 bearing element is in the form of a resiliently deformable wall interposed between the first and second cavities and the displacement element includes a threaded member moveable substantially exclusively in the transverse dimension to deform the deformable wall against the side face of the tab of a fin 25 when operatively inserted in the first cavity.

15. A surfboard fin box according to Claim 13, wherein the bearing means is formed as a separate moveable element which has opposed bearing faces, the moveable element being interposed

30 between the first and second cavities and the displacement- element includes a threaded member moveable substantially exclusively in the transverse dimension to deform the deformable wall against the side face of the tab of a fin when operatively inserted in the first cavity.

16. A surfboard fin box including: a body having an elongate dimension, a transverse dimension substantially at right angles to the elongate dimension and a depth dimension generally at right angles to the elongate and transverse dimensions; an open cavity extending in the depth dimension into the body and having a first cavity portion adapted to receive one or more tabs extending from the proximal portion or the proximal portion of a fin and a second cavity portion spaced from the first cavity portion in the transverse dimension; a bearing element operatively interposable between the first and second cavity portions in the transverse dimension and including a bearing fact portion adapted to bear against the side face of the one or more tabs or proximal portion of the fin in the transverse dimension when the fin is operatively inserted into the first cavity portion; and actuation means operably associated with the bearing element for operatively moving the bearing element towards and away from operative engagement against the one or more tabs or proximal portion of the fin, said actuation means being accessible by way of the second cavity portion; wherein the bearing element is moveable in one or more dimensions including the transverse dimension.

17. A surfboard fin box according to Claim 16, wherein the bearing element is movable in a single direction only having a component in the transverse dimension.